E. I. du Pont de Nemours & Co., Inc.
The Sabine River Works Regional Incinerator was commissioned in March, 1990 to treat hazardous and nonhazardous wastes from du Pont operations in the Gulf Coast area. The incinerator consists of a rotary kiln, afterburner, and a six stage combustion gas scrubbing train with dry and wet scrubbing.A baghouse was included as one stage in the gas scrubbing train. This permits removal of flyash in dry form, while at the same time requiring an upstream quenching step to reduce the combustion gas temperature for protection of the bag material. The gas exiting the baghouse passes through several stages of wet scrubbing. Rather than dispose of the liquid purge from the wet scrubbers as a waste, the purge is recycled to the quencher ahead of the baghouse. Scrubbed solids and salts contained in the purge liquid are dried in the quencher and conveyed to the baghouse, where they are removed as flyash.
Typical design for incinerator off gas scrubbing employs wet scrubbing, with subsequent disposal of the scrubbing liquid as a waste. The du Pont SRW Regional Incinerator, on the other hand, recycles the scrubbing liquid purge for use as the quenching medium required for gas conditioning upstream of the baghouse. This design capitalizes on the presence of the baghouse for removal of salts and ash accumulated in the scrubbing liquid.
The du Pont SRW Regional Incinerator does not produce a continuous liquid waste stream as a result of its operations. A potential waste flow of as much as 200 gallons per minute is avoided.
Details of Reductions
Additional Information :
The scrubbing liquid purge, used to cool the combustion gases in the quencher, replaces as much as 200 gallons per minute of fresh water that would otherwise be required. This translates to a savings on the order of $30,000/year.Incinerators which dispose of scrubbing liquid purges typically must filter the liquid prior to disposal in a wastewater treatment facility, or must maintain some type of sludge treatment. Such facilities vary widely in complexity and expense; costs on the order of $50,000/year could be anticipated, as well as the investment of hundreds of thousands of dollars in the case of a new facility.